Retinitis pigmentosa GTPase regulator-interacting protein 1 (RPGRIP1) specifically interacts with retinitis pigmentosa GTPase regulator (RPGR) []. Mutations in RPGR cause X-linked retinitis pigmentosa type 3 (RP3), whereas mutations in RPGRIP1 cause Leber congenital amaurosis (LCA) []. RPGRIP1 is expressed in the retina and is present in the connecting cilium and outer segments of photoreceptors, where it partially co-localises with RPGR [, ]. RPGR isoforms seem to determine the subcellular targeting of RPGRIP1 [].
Retinal rod rhodopsin-sensitive cGMP 3',5'-cyclic phosphodiesterase () is an oligomer composed of two catalytic chains (alpha and beta), an inhibitory chain (gamma) and a delta chain. This protein interacts with RPGR (retinitis pigmentosa GTPase regulator) [], ARL2 (Arf-like-2) and ARL3. This entry represents the delta subunit [], which is thought to act as a prenyl-binding protein []and participates in the transport of PDE6 catalytic alpha/beta subunits [].
